Conventionally, in the production of a semiconductor device, fine processing by lithography using a photoresist has been performed. The fine processing is a processing method for forming fine convexo-concave corresponding to the pattern on the surface of a substrate by a method including: forming a thin film of a photoresist on a semiconductor substrate such as a silicon wafer; irradiating the resultant thin film with an activating light ray such as an ultraviolet ray through a mask pattern on which a pattern of a semiconductor device is depicted for development; and subjecting the substrate to etching processing using the resultant photoresist pattern as a protecting film. Recently, however, the high integration of semiconductor devices has been progressed and the adopted activating light ray tends to have a shorter wavelength, such as an ArF excimer laser (193 nm) replacing a KrF excimer laser (248 nm). Following such a tendency, the influence of reflection of an activating light ray on a semiconductor substrate has become a large problem. Thus, in order to solve this problem, widely studied is a method of providing a bottom anti-reflective coating between the photoresist and the substrate. For such a bottom anti-reflective coating, many investigations on an organic bottom anti-reflective coating composed of a polymer having a light absorbing group or the like are performed because of easiness of its use and the like. Examples of the organic bottom anti-reflective coating include: an acrylic resin-based bottom anti-reflective coating having both a hydroxyl group, which is a crosslinkable group, and a light absorbing group within the same molecule; and a novolac resin-based bottom anti-reflective coating having both a hydroxyl group, which is a crosslinkable group, and a light absorbing group within the same molecule.
Characteristics required for the bottom anti-reflective coating include: a large absorbance to light or radiation; no intermixing with a photoresist (being insoluble in a photoresist solvent); no diffusion of low molecule substances from the bottom anti-reflective coating to the photoresist at the upper layer during heating and baking; a dry etching rate larger than that of the photoresist, and the like.
Further, recently, for solving a problem of the wiring delay that has become apparent as the miniaturization of a pattern rule of the semiconductor device has progressed, the use of copper as a wiring material is studied. Then, together with it, a dual damascene process is studied as a method for forming a wiring on the semiconductor substrate. Then, in the dual damascene process, a bottom anti-reflective coating is formed on a substrate having a large aspect ratio in which a via hole is formed. Therefore, for the bottom anti-reflective coating used in this process, filling characteristics capable of filling holes without voids, planarization characteristics capable of forming a planar film on the substrate surface, and the like are required.
As an underlayer film between the semiconductor substrate and the photoresist, the use of a film known as a hardmask containing a metal element such as silicon and titanium is performed (see, for example, Patent Document 1). In this case, the resist and the hardmask have components largely different from each other, and thus, the removing speeds of the resist and the hardmask by dry-etching largely depend on the type of a gas used for dry etching. Then, by appropriately selecting the type of a gas, the hardmask can be removed by dry etching without a large decrease of the film thickness of the photoresist. Thus, in the production of semiconductor devices in recent years, for achieving various effects such as the anti-reflection effect, a resist underlayer film has become disposed between the semiconductor substrate and the photoresist. Although studies of a composition for a resist underlayer film have been performed until today, due to the diversity of characteristics required for the composition and the like, development of a novel material for the resist underlayer film is desired.
A composition or a pattern forming method using a compound having a silicon-silicon bond is known (see, for example, Patent Document 2).
A bottom anti-reflective coating forming composition containing an isocyanate group or a blocked isocyanate group is disclosed (see, for example, Patent Document 3).
A hardmask material using a resin containing a polycarbosilane is disclosed (see, for example, Patent Document 4 and Patent Document 5).    Patent Document 1: Japanese Patent Application Publication No. JP-A-11-258813    Patent Document 2: Japanese Patent Application Publication No. JP-A-10-209134    Patent Document 3: International Publication No. WO 2000/01752 pamphlet    Patent Document 4: Japanese Patent Application Publication No. JP-A-2001-93824    Patent Document 5: Japanese Patent Application Publication No. JP-A-2005-70776